DETERMINATION OF GLUTATHIONE IN PHARMACEUTICALS AND COSMETICS BY HPLCWITH UV AND FLUORESCENCE DETECTION

A selective HPLC determination of reduced glutathione (GSH) in pharmac eutical and cosmetic formulations is described based on prechromatogra phic derivatization with 4-(6-methylnaphthalen-2-yl)-4-oxo-2-buteneoic acid. The derivatization reaction is rapid under mild reaction condit ions (10 min at ambient temperature and pH 7.5) and the excess reagent can be removed by liquid-liquid extraction. The thiol adducts were ch romatographed on a C-8 column using 0.05 M triethylammonium phosphate (pH 4.0)-acetonitrile 68:32 (v/v), as the mobile phase; UV and fluores cence detection (l(em) 450 nm, l(exc) 300 nm) were both used. The stru cture of the thiol adducts was confirmed by H-1 and C-13 NMR spectra u sing sodium methanethiolate as thiol nucleophile.